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The
last section of the largest fossil ichthyosaur in the world has |
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The ambitious excavation project was masterminded by Dr Elizabeth Nicholls, intrepid and determined curator of marine reptiles at the Royal Tyrrell Museum. The extreme conditions would have deterred a lesser mortal: Over the past three years, Nicholls has overcome countless obstacles to extract the sleeping giant from its limestone bed. Set in the bank of a white-water river and submerged for most of the year due to flooding, the site had to be cleared of dense vegetation before it could be mapped out. Work was further hindered by the extreme northern climate, the threat of attack by grizzly bears, and constant plagues of mosquitoes. |
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| Powerful equipment was needed to excavate the fossil, which was carefully divided into unavoidably heavy sections - the skull alone weighed more than 4,000 kilograms. And due to the inaccessibility of the region, the transportation of each precious segment of the ichthyosaur, from parts of its huge paddle-like flippers to its vast bottle-nosed snout, had to be undertaken by helicopter. | |
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 However, Nicholls may now take comfort from the fact that she has finally managed to wrest from nature one of its most closely guarded secrets. Previously, scientists believed that the growth of prehistoric marine reptiles was limited to a maximum length of 15 metres, as in the case of Shonisaurus, the Triassic marine reptile found in the Nevada desert.
In the light of Nicholls' research, this assumption is no longer valid:
a gigantic 23 metres long, with an intact 5.8-metre-long skull, the
Sikanni ichthyosaur is an impressive 1/2 times larger than any existing
specimen, a size previously believed impossible. The question now
in the minds of the scientific community is: How did it grow so large?
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Nicholls believes that the answer may lie in the ichthyosaur's dentition, which should reveal the type of prey it fed on. Most huge marine creatures are "filter-feeders", which obtain their food by straining the surrounding seawater through a series of plates in their jaws. The rare exception is the sperm whale, which has teeth, and can therefore seize and chew large prey such as the giant squid. In order to establish the ichthyosaur's diet and eating habits, Dr Nicholls is tackling the herculean task of cleaning and analysing the fossil. Whatever her research reveals, it will open new horizons. "It's a new page in the history of our planet", she says. |
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| Cave art in Borneo l Sacred mountain discovery l Giant ichthyosaur fossil l Submerged ancient cities l Imagery of the Maya | |